On Thu, Jan 03, 2019 at 02:29:34AM +0100, Marek Vasut wrote:
> The touchscreen can have a reset GPIO connected to it, add support
> for such an arrangement.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> Cc: Olivier Sobrie <olivier@xxxxxxxxx>
> Cc: Philipp Puschmann <pp@xxxxxxxxx>
> To: linux-input@xxxxxxxxxxxxxxx
> ---
> V2: No change
> V3: Use devm_add_action_or_reset() for reset GPIO teardown
> ---
> drivers/input/touchscreen/ili210x.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
> index 436bfedb6769..a193ddb06e10 100644
> --- a/drivers/input/touchscreen/ili210x.c
> +++ b/drivers/input/touchscreen/ili210x.c
> @@ -5,6 +5,7 @@
> #include <linux/input.h>
> #include <linux/input/mt.h>
> #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>
> #define MAX_TOUCHES 2
> #define DEFAULT_POLL_PERIOD 20
> @@ -44,6 +45,7 @@ struct ili210x {
> struct input_dev *input;
> unsigned int poll_period;
> struct delayed_work dwork;
> + struct gpio_desc *reset_gpio;
> };
>
> static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
> @@ -167,11 +169,19 @@ static const struct attribute_group ili210x_attr_group = {
> .attrs = ili210x_attributes,
> };
>
> +static void ili210x_power_down(void *data)
> +{
> + struct gpio_desc *reset_gpio = data;
> +
> + gpiod_set_value_cansleep(reset_gpio, 1);
> +}
> +
> static int ili210x_i2c_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct device *dev = &client->dev;
> struct ili210x *priv;
> + struct gpio_desc *reset_gpio;
> struct input_dev *input;
> struct panel_info panel;
> struct firmware_version firmware;
> @@ -185,6 +195,22 @@ static int ili210x_i2c_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> + reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(reset_gpio))
> + return PTR_ERR(reset_gpio);
> +
> + if (reset_gpio) {
> + error = devm_add_action_or_reset(dev, ili210x_power_down,
> + reset_gpio);
> + if (error)
> + return error;
> +
> + gpiod_set_value_cansleep(reset_gpio, 1);
You already requested it as "high", there is no need to try to driver it
high again here.
> + usleep_range(50, 100);
> + gpiod_set_value_cansleep(reset_gpio, 0);
> + mdelay(100);
usleep above but mdelay here? I do not think we have to spin here.
> + }
> +
> /* Get firmware version */
> error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
> &firmware, sizeof(firmware));
> @@ -217,6 +243,7 @@ static int ili210x_i2c_probe(struct i2c_client *client,
> priv->input = input;
> priv->poll_period = DEFAULT_POLL_PERIOD;
> INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
> + priv->reset_gpio = reset_gpio;
>
> /* Setup input device */
> input->name = "ILI210x Touchscreen";
> --
> 2.19.2
>
Thanks.
--
Dmitry
